Optical systems for vehicle operator monitoring have been used in various applications including, but not limited to, occupant detection and occupant security. The proposed design and integration of such conventional optical systems have included many performance and functionality issues, which impacts cost and complexity in the overall design of the passenger compartment area.
Referring to FIGS. 10A-11, conventional integration designs have located an imager 1 (i.e., a camera) of the optical system within the instrument cluster 2, on the A-pillar, or in the center console. In such implementations, the imager 1 was located in a directly opposing relationship, relative to the driver, to directly capture images of the driver during the operation of the vehicle. However, in order to ensure the proper operation of such an optical system, the imager 1 must not be obstructed at any time. As seen in FIG. 10B, by locating the imager 1 in the instrument cluster 2, the imager 1 is susceptible to obstructions caused by the driver's hands, wrists, and arms when the driver moves his hands from the 2-o'clock and 10-o'clock positions (FIG. 10A) to a new position proximate the 12-o'clock area (FIG. 10B) of the steering wheel 3. Referring to FIG. 11, if the imager is located about a headliner area, the brim 4 of an operators' hat 5 may obstruct a portion of the driver's face 6. In yet another situation, if the imager is located in the A-pillar area, obstructions to the driver's face may be reduced, however, an A-pillar located imager is limited to capturing a partial profile of the driver's face due to the off-center location of the imager.
As such, a need exists for improving optical systems for vehicle operator monitoring.